Energy-efficient real-time task scheduling with temperature-dependent leakage

Leakage power consumption contributes significantly to the overall power dissipation for systems that are manufactured in advanced deep sub-micron technology. Different from many previous results, this paper explores leakage-aware energy-efficient scheduling if leakage power consumption depends on temperature. We propose a pattern-based approach which divides a given time horizon into several time segments with the same length, where the processor is in the active (dormant, respectively) mode for a fixed amount of time at the beginning (end, respectively) of each time segment. Computation is advanced in the active mode, whereas the dormant mode helps reduce the temperature via cooling as well as the leakage power consumption. Since the pattern-based approach leads to a steady state with an equilibrium temperature, we develop a procedure to find the optimal pattern whose energy consumption in steady state is the minimum. Compared to existing work, our approach is more effective, has less run-time scheduling overhead, and requires only a simple scheduler to control the system mode periodically. The paper contains extensive simulation results which validate the new models and methods.